ConfirmDialog

I want to add Confirmation handling before deleting data from database. Following code is implemented for it.
But when I click on Delete button on screen, I get to see Dialog box only with “Please Confirm”. The rest of the information i.e Buttons and Warning message doesn’t appear. Please help.

Vaadin version used by me 7.1.5.
confirmdialog version is 2.0.4

    deleteButton.addClickListener(new Button.ClickListener() {

		@Override
		public void buttonClick(ClickEvent event) {
			
			final UI main = event.getButton().getUI();
			
			
			ConfirmDialog.show(main, "Please Confirm:", "Are you really sure?",
			        "I am", "Not quite", new ConfirmDialog.Listener() {

			            public void onClose(ConfirmDialog dialog) {
			                if (dialog.isConfirmed()) {
			                    // Confirmed to continue
			                	LOG.info("Clicked on Yes");
			                } else {
			                	LOG.info("Clicked on NO");
			                }
			            }
			        });
    }});